使用特征正交分解型谱表示法的汽车受路面激励随机模拟

STOCHASTIC SIMULATING FOR MULTIVARIATE ROAD ROUGHNESS WITH SPECTRAL REPRESENTATION METHOD BASED ON PROPER ORTHOGONAL DECOMPOSITION (POD)

将特征正交分解型谱表示法用于模拟汽车受路面激励。首先给出了路面不平度对汽车输入的位移随机激励的谱描述。基于路面激励的功率谱矩阵,结合特征正交分解(POD,ProperO rthogonalDecomposition,)型谱表示法的模拟表达式,给出了路面激励的显式POD分解,定义了汽车的“路面激励模态”,推导了路面对汽车输入激励随机模拟的简化计算公式。该方法可用FFT来减少计算量以提高计算速度。它由于完全消除掉了原型谱表示法的Cholesky分解过程而具有较高的计算效率和更明确的物理意义。最后,通过对一个四轮轿车在国标GB7031-87中的A级路面不平度下受到的位移随机激励进行模拟,说明了该方法的有效性。

Stochastic excitation acted on automobiles due to multivariate road roughness is described in detail firstly.Proper orthogonal decomposition(POD) of random multivariate processes is defined.Then,to simulate the stochastic excitation,a set of simplified formulas based on the spectral representation method and POD is given,which can reduce computation with FFT to speed up computing.Since the time-consuming Cholesky decomposition is removed,the simplified method is more efficient than the original spectral representation method.By defining the 'road roughness mode' vividly,the physical meaning of POD and this method are clarified.Simulation of the displacement excitation acted on a four-wheeled car is taken as an example.The validity of this method is verified.